we know that
The measurement of <u>the external angle</u> is the semi-difference of the arcs it includes.
In this problem
![21\°=\frac{1}{2}[arc\ RU-arc\ SU]](https://tex.z-dn.net/?f=21%5C%C2%B0%3D%5Cfrac%7B1%7D%7B2%7D%5Barc%5C%20RU-arc%5C%20SU%5D)
Solve for the measure of arc SU
![42\°=[arc\ RU-arc\ SU]](https://tex.z-dn.net/?f=42%5C%C2%B0%3D%5Barc%5C%20RU-arc%5C%20SU%5D)
therefore
the answer is
The measure of the arc SU is 
Answer:option B & D are correct
Step-by-step explanation:
Given options are
A B C D E
Tether ball pole shadow 1.35 1.8 3.75 0.6 2
Flagpole shadow 3.4 4.08 8.35 1.36 4.8
Ratio of corresponding height & shadows should be same
3 meter tall tether ball pole and a 6.8 tall flagpole
=> Ratio = 6.8/3 = 68/30 = 34/15
A - 3.4/1.35 = 340/135 ≠ 34/15( 306/135)
B - 4.08/1.8 = 408/180 = 34/15 = 34/15 ( Correct option)
C 8.35/3.75 = 835/375 = 167/75 ≠ 34/15( 170/75)
D 1.36/0.6 = 136/60 = 34/15 = 34/15 ( Correct option)
E 4.8/2 = 48/20 = 12/5 = 36/15 ≠ 34/15
option B & D are correct
Let us convert all figures into decimals so that we can compare them easily.
Monday 0.3
Tuesday 15% = 0.15
Wednesday 1/6 = 0.1666
Thursday 0.2
Friday 1/8 = 0.125
Clearly, I spent the least amount of time on Friday using IT and the time is 0.125 or 1/8.
